Here's what's goin on:

Just installed a Mikuni 44PHH on a wrap around header.

Engine is an 84-85 12A with less then 80k miles on it.

Internal condition of engine is not known.

Engine started running a little hotter around June last year. Hasn't ever gotten cooler. Never overheats, just runs hotter. New radiator cap and coolant and still no drop.

Car had started 3 times with the mikuni setup and I drove it twice. Nothing hard. Just around the block.

Decided to check timing to see if it was correct since it was running rough.

Car would not start. Tried everything. No way to check timing because I can't get it to start.

OMP is zip tied 3/4 open.

Battery has been charged to full twice.

Car wouldn't start before the first 3 times until I connected the fuel return line.

Fuel pressure is set at 2.5 PSI since that's the only way it would start.

I've been pulling the dizzy out and turning the gear to different notches. Still no start.

Been at least a year since I've put in new plugs. Never got new wires. Haven't tested plugs yet.

When I drove it around, it would backfire alot. But only when I left the clutch engaged while slowing down.

When accelerating the two times I drove it, it went real slow for a few seconds while it ran real rough, then it would instantly get good and kinda go. Not as good as my Nikki.

Car shook bad when the engine was running even though I had adjusted the carb to smooth it out. It idled around 2k rpm.

I think that shoudl be enogh info. I have no idea what's goin on. It jsut won't start and it really pisses me off. Could the spark plugs be bad? Could it be internals? I've never driven it real hard. I do think that the timing has been off for the past year though. Never checked it. This is so aggravating.

 

I ran my Mikuni at 4.5 psi with no return line. Ran fine except for a liitle bog between 7-8k, flat shifting wot.

Sounds like you have several issues to address.

Check the FSM for the proper alignment of the dis. Once the dis is in, set the clamping screw in the center of the slot, that should get the timing close enough to fire.

Check the spark plugs, clean or replace as needed.

I made my own omp lever to the carb from one that came off a 2nd gen, and I assume you have the omp lines hooked to the carb.

If the engine was running fine before the carb and intake change, then it is most likely a tuning issue with the carb itself. However it could also be a weak fuel pump, (my stock one would not put out enough psi for the Mikuni), a vaccum leak and now a timing issue.

Get the timing set and up the fuel pressure. If you are using a fuel pressure regulator with a guage and a return line, the regulator needs to go after the carb.

You didn't say anything about the condition of the mikuni, if it has sat for awhile, it may need gone though and cleaned.

 

The carb is in great condition. FSM????? I made hte leading mark on the pulley line up with the pin and tookout hte distributor and aligned it with the dot and mark on the end of the shaft. Didn't do a thing. The car wouldn't start before I connected the return line and it didn't start after that until I turned the fuel pressure down to 2.5. I installed a brand new Carter P4070 fuel pump capable of 6 PSI. No fuel pump problems. I have the FPR before the carb. Is that the wrong spot for it? And my FPR is a Mr. Gasket one that has the PSI on it so there's no need for a guage. I still need to check the spark pugs which I will do tomorrow maybe. If not tomorrow it will be next week before I can work on her again.

 

FSM= Factory Service Manual. You can download the one for the '85 at:

http://www.wankel.net/~krwright/cars/rx7/85_manual.html

 

I put the dizzy in just like the manual says. Didn't do a thing. I'll be checking the spark plugs soon. May have to push start it.

 

Actually, the mr gasket fpr is slightly off. If you have it set at 2.5, it is roughly 3-3.25 This is how my current and last one (both mr gaskets) have been.

 

THIS SOUNDS LIKE MY PROBLEM TOO!!!

I run a holley 600cfm carburetor with .56 primaries on a stock port 12a. Kettleman said that when tuned right (which mine is probably not) you can run a holley 600 with my setup no problem. But when i try to accelerate...my car shakes a bit til it gets into the high rpms.

 

So if I have the distributor set to the FSM specifications, have good plugs, fuel pump, regulator, carb, and everything is set right and it still won't start what could it be??? Could it be internals? How many wooshes are there supposed to be per shaft revolution?

 

When it was running did you check for vacuum leaks around the carb and intake?
Also- when I used a Mikuni there was no need for the return line. You should cap it off or get a fuel line banjo with only one fuel line port.
You running an aftermarket high volume pump? If not- you need one anyway.
If it's running HOT I'd say it's too lean? When I ran a Mikuni- it ran best with a slightly rich mixture. The intake manifold was also cold. REALLY cold, with frost forming on the runners..
Basically- if the car was running right before the Mikuni swap, I'd venture to say you need to double back and check the install procedures again. Pay less attention to the timing for right now- look elsewhere for the culprit. Fuel delivery being on the top of the list.

Also- how 'used' is the Mikuni? Are any of the jets clogged? You may want to inspect and blow out the jets with compressed air. See if the AP valve is working, etc.. I'm not an expert on carbs (by any means) but I think you might need to work this side of the issue first. Just my .02 measly cents

 

I'm over the timing issue. That will be tuned after the car runs. The fuel pump is a brand new Carter P4070 and all new fuel lines in the fuel pump area and to the carb. The jets are also brand new and were installed specifically for my application the week before delivery. The carb is in near perfect condition. I'm going to recap the return line and hopefully I can push start her. Not really much street for that where I am. I probably had a vaccuum leak with the Nikki since I had removed the rats nest and had some tubes still open, but nothing that went into the carb or intake. Just the butterfly valve in the spacer and maybe some other things. The fuel pressure regulator I recieved looks like it's a Mr. Gasket, but could possibly be a purolator and I hear the purolators are bad. Would it keep my car from starting though? How many wooshes are there per rotation of the eccentric shaft? I've never checked compression on the engine before.

 

It would be highly unlikely that the motor would be blown cause you recently swapped carbs, unless the jetting was ultra-lean or something like that.

The FPR should not be much of a factor when starting and idling the car- it does become a factor when you are trying to sustain high speed runs or WOT. You'd be better off trashing the dial and getting a holley fpr instead. The Mikuni 44 I used on my old 13B 4port had a purolator regulator and it was pure junk.

I'd hook up a fuel pressure guage and verify pressure to the carb after the regulator (once you get it running) just to keep it honest. IIRC_ my 13B loved about 3.0 psi on fuel delivery, using a Weber fuel pump.

I'd really check for vacuum leaks right now and make sure linkages are working w/out any binding and stuff like that.

If you want to check for 'whooshes', they should all be 'strong', 3 x.

 

There are only two open tubes on the carb and I was told they were for venting adn not to cover them. They're really long. Here's a pic:

The top two marked tubes are what I was told to keep open. The linkages work fine.

 

Are the bottom two ports for the OMP, or do you have tapped ports on the intake runners for those? Also- IIRC- two of those vac ports are for the distributor advance, if so desired.

When I say vac leak- check where the carb mates to the manifold, and where the manifold mates to the block. Best if the car is running and spray some carb cleaner in the area to see if RPM shifts around.

If you want some detailed info on the Mikuni- you may want to google 'Fast Freddy's' in california. Nick VanNugteren. He owned Rotary Reliability and Racing and used Mikuni's on all his set-ups. His shop might be able to diagnose some issues.

 

The bottom tubes are for the OMP lines. I can't check for vac leaks because the car does not start. I assume you used the Holley FPR for 1-4 psi?

 

Yes.

Is the car flooded as a result of the starting issues? Will she kick with just a light bit of starting fluid sprayed into the carbie?

 

The engine turns over just like normal, but never starts. Never tries to start, never bogs down. I'm gonna go get a Holley FPR and guage. Stupid question: How do I know if the engine is flooded?

 

My nose tells me. Strong odor of gas and the car won't start.
If you pull the plugs, they would be wet with gas.

There is a thread on 'un-flooding' a rotary. Search for it or just wait a loooong time before kicking her over again. Take out a plug on #1 and #2 and let her sit.

Starting fluid should let you fire her up- just use a weeeee bit. 1/2 second squirt- kick it over.

Did you mess with the idle adjustment/mixture screws a lot? Do you know what the base settings are from lightly seated? If not- you need to get that info and make sure they are set correctly.

 

WHen it was running I set the mixture screws to where it ran the most "smoothly". It's been sitting for 2 or 3 days without any activity. Shouldn't that have unflooded it? I don't smell gas unless I get real close to the carb. I still haven't checked the plugs cause they are going to be a pain in the ***. I still have the AC in even though it doesn't do anything. I don't have starting fluid. Never heard of it.

EDIT: Should I be able to hear the swooshes with the carb on? I hear swooshes, but they are quiet and sometimes sound like drawn out leaks. I don't think I'm turning the pulley quickly enough if that matters.

 

This is what my leading plug on the front rotor looks like:

 

Well that color ain't too bad at all.
Have you verified that gas is indeed getting fed to the motor? Try taking off the air cleaner assembly and looking down the 'barrels' and see if gas is squirting down. Also- have you checked for spark?

Edit- starting fluid can be had at any automotive store. I use it when I need to fire up a really cold tractor or old carb'd car in the winter. Just use it SPARINGLY.

 

Haven't checked for either. I know fuel is getting through the fuel line.Don't know if it's getting into the carb. I guess checking for spark you just take the plug out but keep it in the wire?

 

Yup. Just hold the wire and plug to ground (on the irons or on a bolt along the body) and have someone crank it. May want to use insulated pliers too. Turn the lights down too, you'll see it if you've got it.

However- I'd still suspect fuel delivery as the culprit.

 

I'm waiting for my dad to get home to do some of this stuff. I'm alone right now. I have to cap the return fitting, check flow through the fuel line, chekc flow throught carb, and check spark. I saw some fuel sitting in one of hte velocity stacks, but it was pretty brown. Is it supposed to be brown or clearish? The car needs an oil change too. Could there be too much oil in the gas to start it? I have the OMP ziptied 3/4 open all the time.

 

Well- I never had the OMP wired open. The Mikuni I had basically had a stock style rod actuating the OMP. The more you gave it the gas, the farther it opened. However- I doubt the additional oil would be causing any starting problems. As a matter of fact, if it were- you're plugs would be oil fouled, which they are not.

Yes- gas will turn brownish. It gets varished with time and exposure.

Definately verify the basics before you start messing with jets and stuff. If you can get her to run- check for those vac leaks...

 

I had to get the fittings for the FPR. They're a little loose where they screw in. I suppose it needs tephlon tape. They didn't have enough of one fitting and I think the one I got for the guage is wrong. Sure would be nice of Holley to include fittings in their stuff like Carter does.